The subject matter disclosed herein generally relates to electro-mechanical systems, and more particularly to an electric motor with a passive integral brake.
Certain applications for electro-mechanical actuators require that an electro-mechanical actuator hold a load in a stationary position after electrical power to operate the electro-mechanical actuator has been removed. One approach to holding a stationary position absent electrical power is the use of a friction device that drags at all times. Examples of friction devices include friction pads, ball ramps, heavily pre-loaded rolling element bearings, and skewed roller bearings. The ever-present drag produced by these friction devices typically requires over sizing of the drive motor and reduces actuator efficiency.
Using an actively controlled brake can alleviate the inefficiency associated with a continuously dragging brake; however, the actively controlled brake adds complexity by requiring a control system for operation. Some actively controlled brakes use electrical power to engage the brake, while others use additional electrical power to release the brake. The inclusion of an actively controlled brake in an electro-mechanical actuation system also increases the overall size and weight of the system, and may demand additional electrical power to set and release the actively controlled brake.